Drill.



T. J. THOMAS.

' DRILL.

APPLIOATION IILED MAY 6,1911.

1,035,270. Patented Aug. 13, 1912.

WW4 mama d w77mm a yam v UNITED STATES PATENT OFFICE.

THOMAS J. THOMAS, 0F MINERSVILLE, PENNSYLVANIA.

DRILL.

T 0 all whom it may concern:

Be'it known that I, THOMAS J. THOMAS, a citizen of the United States, residing at Minersville, in the county of Schuylkill and 'State of Pennsylvania, have invented new conveniently removed therefrom when worn.

' The above mentioned and other objects are attained by the construction, combinations and arrangements of parts, as disclosed in the drawing, set forth in this specification, and particularly pointed out in the In the drawing, form ng a portion of this specification and in which like numerals of reference indicate similar parts in the several views :-Figure l is a side view of the.

drill. Fig.2 is a vertical section. Fig. 3

'is a detail vertical section of the bit retaining member or clamping sleeve. Fig. 4 is a detail perspective view of one of the bits. Fig. dis a detail horizontal section taken on the line 55 of Fig. 2. Fig.6 is a view similar to Fig.- 2 showing a slightly modified form of my inventio My improved drill as herein illustrated consists of a shank or stock 1 which is provided at one end with an externally threaded head 2. A bit retaining member or clamping sleeve is shown at 3, and as shown the said sleeve is provided with,a cylindrical threaded bore 4 and with a stripped substantially conical shaped bore 5. The construction of the sleeve 3 is such that its internally threaded portion is adapted for engagement with the externally threaded portion of the head 2 upon the stock or shank 1. The construction of the sleeve 3 is also such that it is provided with an enlarged bore with a reduced bore which incident to its construction or formation is provided with downwardly and inwardly tapered walls. The lower edge portion of the sleeve 3 is beveled to form an annular shoulder 6 which is adapted to abut against shoulders 7 formed upon side bits 8.

The side bits are provided with upwardly extending substantially wedge shaped extremities or portions 9 which are provided with curved outer faces 10 and with flat inner faces 11.. By constructing the bits in Specification of Letters Patent.

Application filed May 5, 1911.

Serial No. 625,382.

this manner it will be seen that when they have been properly associated with respect to each other in the reduced bore 5 of the sleeve 3 a substantially wedge-shaped passage is formed between the faces 11. This passage receives a correspondingly wedgeshaped upper extremity of a centrally located bit 12 the side faces of which being adapted for frictional engagement with the faces 11 of the extremities 9 carried by the bits 8. The bits 8 are provided with downwardly and outwardly inclined inner and outer faces 13 and 14, and as shown the faces 13 are suitably spaced from the side faces of the centrally located bit 12. The lower edges of the bits 8 are beveled downwardly and outwardly as shown at 15. The

lower extremity of the centrally located bit extends downwardly beyond the plane of the lower extremities of the bits 8 and is pointed as shown at 16. I

In operation, when it is desired to assemble the various parts forming the herein described tool the upper extremities 9 are inserted in the reduced bore 5 of the retaining member or clamping sleeve 3 and are arranged so that their inner faces are spaced from each other to form the passage for the reception of the upper extremity of the centrally located bit 12. After the centrally located bit 12 has been properly positioned within the sleeve 3, the threaded head 2 upon the shank 1 can be engaged with the sleeve3 and can be properly adjusted, as

Patented Aug. 13, 1912. y

will be appreciated so that the lower faceof. the said head frictionally engages the upper edge portions of the bits. manner it will be seen that the side faces of the centrally located bit are effectively forced into frictional engagement with the inner faces of the extremities 9 of the bits 8, and it will be further seen that the outer curved faces 10 of the extremities 9 will be effectively forced into frictional engagement with the walls of the reduced bore 5 in the sleeve or retaining member 3. In order to effectively hold the sleeve 3 in its adjusted position upon the head2 I provide the lat ter with a clamping nut 17 which is adapted for operation so that its lower.face can be frictionally engaged with the upper edge In this i 1 clamping sleeve 21'. 'l he passages 19 and 20 are adapted to receive a removable wedge key 22. In this form of my invention I ob viate the use of the threaded portions described in the preferred form of my inven: tion and rely entirely upon the key 22 as means for forcing the lower extremity of the'shank or stocklS into frictional engagement with the upper edge portions of the bits. By providing the shoulders 7 it will be seen'that when stress is ap lied to the shank 1 the strain will be equa ly distributed to the bits and will be applied equally to the shoulders 7 and to the upper faces or edge portions of the extremities 9. i

I claim A drill comprising a shank, a sleeve removably mounted on the shank and provided with a large and a reduced passage,

said reduced passage having downwardly and inwardly tapered walls, spaced bits having a relatively broad semicircular substantially wedge shaped" upper portion disposed in the reduced passage of the sleeve, the lower portion of the said bit being relatively narrow and extending downwardly and outwardly from the center of the said upper portion anddisposed at right angles thereto, and a centrally located bit having a Wedge shaped upper portion adapted for frictional engagement with the relatively broad upper p'ortions'of the said bits substantially as and for the purpose described In testimony'whereof I- affix my signature in presence of two witnesses.

THOMAS J. THOMAS.

Witnesses: I

EUGENE J. SULLIVAN THOMAS W. FEssLER. 

